one-of ( symbol1 symbol2 -- obj1/obj2 first? ) (original) (raw)
one-of ( symbol1 symbol2 -- obj1/obj2 first? )
Vocabulary
namespaces.extras
Inputs
| symbol1 | an object |
|---|---|
| symbol2 | an object |
Outputs
| obj1/obj2 | an object |
|---|---|
| first? | an object |
Definition
: one-of ( symbol1 symbol2 -- obj1/obj2 first? )
2dup [ get ] bi@ 2dup xor* over
[ [ 4drop ] 2dip ] [ one-variable-only ] if ;